US Patent Issued to Sandisk Technologies on Oct. 28 for "Method for dual wavelength overlay measurement with focus at a photoresist top surface and apparatus for using same" (Japanese Inventor)

ALEXANDRIA, Va., Oct. 28 -- United States Patent no. 12,456,693, issued on Oct. 28, was assigned to Sandisk Technologies Inc. (Milpitas, Calif.).

"Method for dual wavelength overlay measurement with focus at a photoresist top surface and apparatus for using same" was invented by Katsuya Kato (Yokkaichi, Japan).

According to the abstract* released by the U.S. Patent & Trademark Office: "An array of alignment marks can be formed in a substrate, and at least one material portion can be deposited and patterned. A photoresist material layer can be deposited and patterned to provide a kerf-region photoresist material portion. The overlay between the kerf-region photoresist material portion and a proximal alignment mark is measured employing a u...